EYES ON
Idea that it is something blocking oxygen uptake to hemoglobin. Anything that could bind to hemoglobin and change its conformation could interfere with oxygen-heme binding stability. Question is does virus code for a protein binding to hemoglobin? Could be small. Get a medical lab to isolate hemoglobin from an infected patients blood preserving pH and ionic strength and O2 sat and run a GC mass spec and see if oxygenated hemoglobin is the right mass. Test against a stored blood sample of hemoglobin from 6+ months ago.